[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxyl]-terminated compounds

ABSTRACT

A compound according to formula (I) can be part of a heat-curable resin composition based on polymaleimide resin systems comprising such compound as co-monomer: 
     
       
         
         
             
             
         
       
     
     wherein D is an x-functional group; and x is an integer ≧2; with the proviso that the x-functional group D is not a polycarbonate with an average molar mass in the range of 15000 g/mol to 150000 g/mol. A crosslinked resin is obtainable by curing such composition. The compounds can be used in structural adhesives, matrix resins for fiber prepregs, moulding compounds, and structural and/or electrical composites.

FIELD OF THE INVENTION

The present invention relates to[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compounds and toheat-curable resin compositions based on polymaleimide resin systemscomprising such [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminatedcompounds as co-monomers. The present invention also relates tocrosslinked resins obtainable by curing such compositions. Compounds ofthe present invention can be used amongst others in the followingfields: Structural adhesives, matrix resins for fiber prepregs, mouldingcompounds, as well as structural and/or electrical composites.

BACKGROUND

Curable thermosetting compositions based on polymaleimide buildingblocks and co-monomers are established resins for fiber composites,adhesives, moulding and potting compounds. These resins are known fortheir high temperature resistance.

The co-monomer part of the composition influences several uncured andcured resin properties. Importantly, a suitable choice of thisco-monomer part is required for modifying the processing properties ofthe uncured resin, in particular to adjust rheological properties suchas flow and viscosity and to influence the cure kinetic properties.

Desired properties of the cured polymaleimide/co-monomer system includehigh glass transition temperature (Tg), high modulus retention attemperatures around 250° C., high heat resistance in terms of thermaloxidative stability (TOS) and durability, high toughness and damagetolerance and temperature cycling resistance to microcracking. Furtherdesired properties include low moisture and solvent uptake and lowdielectric constant (DC).

Many chemical concepts have been devised for generatingpolymaleimide/co-monomer systems. For applications as resins for fiberreinforced composites, structural adhesives and electrical andelectronic appliances polymaleimide/alkenylphenol andpolymaleimide/alkenylphenoxy based systems were found to be the mostsuccessful.

Alkenylphenol co-monomers are disclosed in U.S. Pat. No. 4,100,140(1978).

Curable thermosetting compositions based on polymaleimides andalkenylphenoxy compounds are known, for example, from U.S. Pat. No.4,789,704 (1988), 4,826,929 (1989), 4,808,717 (1989), 4962,161 (1990),5,120,824 (1992), 4,873,284 (1989), 5,023,310 (1991), 5,023, 310 (1991),5,070,154 (1991) as well as US 2008/0075965A1 (2008), and CN104628544A(2015).

Desirable properties of uncured bismaleimide/co-monomer systems withrespect to their use for composites and fiber reinforced composites inparticular, include low viscosity at processing temperature, lowprocessing temperature, sufficient pot life at processing temperature,good storage stability in the form of resins and intermediate productssuch as prepregs, glues or compounds as well as fast cure kinetics (fastreaction of co-monomers and polymaleimides) during manufacture ofcomposites.

Few investigations relating to fast curing bismaleimide/co-monomersystems have been conducted so far, which is unfortunate in view of thefact that fast cure kinetics enable curing in short periods of time thusfacilitating processing to be performed in an advantageous manner. U.S.Pat. No. 4,288,583 (Zahir, Wyler, 1981) discloses the results of onesuch investigation. In particular, U.S. Pat. No. 4,288,583 disclosesmixtures of polymaleimides und propenyl-substituted phenols, e.g.o,o′-di(1-propenyl)bisphenols, as fast curing polymaleimide/co-monomersystems. CN104628544A (Liu et al., 2015) as well is directed at fastcuring systems and discloses polymaleimide/trifunctionalpropenyl-endcapped co-monomer systems which provide fast curing kineticsdue to their triplicate functionality.

Cured products obtained from the bismaleimide/co-monomer systemsdisclosed in U.S. Pat. No. 4,288,583, however, exhibit a pronouncedtendency to absorb water (particularly pronounced under hot/wetconditions) resulting in several disadvantageous characteristics of therespective products, including the following: lowered glass transitiontemperature (Tg), weakened mechanical properties at elevatedtemperatures, increased tendency to suffer from microcracks underconditions of thermal cycling when used in fibre reinforced composites,impaired electrical properties (increased dielectric constant). Thepolymaleimide/trifunctional propenyl-endcapped co-monomer systemsdisclosed in CN104628544A, on the other hand, suffer from poorprocessability as viscosity is increased significantly by thetrifunctional co-monomers.

In view of the above an object of the present invention resided inproviding co-monomers for use in polymaleimide/co-monomer systems aswell as such polymaleimide/co-monomer systems characterized by fast curekinetics (fast reaction of co-monomers and polymaleimides) and goodprocessing properties, yielding copolymers with a low tendency to absorbwater thus resulting in copolymers with (i) good mechanical propertiesat elevated temperatures and/or (ii) a low tendency to suffer frommicrocracks under conditions of thermal cycling and/or (iii) goodelectrical properties (low dielectric constant).

DETAILED DESCRIPTION OF THE INVENTION

This object is achieved by[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compoundsaccording to formula (I)

-   -   wherein    -   D is an x-functional group; and    -   x is an integer ≧2;    -   with the proviso that    -   the x-functional group D is not a polycarbonate with an average        molar mass in the range of 15000 g/mol to 150000 g/mol.

(2-Ethoxy-5-trans-1-propen-1-yl)-phenol is commonly called vanitrope. Avanitrope-terminated polycarbonate of specific molecular mass as suchhas been disclosed in the prior art (cf. JP3220567B2, paragraph [0047],example 4: Average molar mass of 20800 g/mol and weighted average molarmass of 51200 g/mol), however, no mention was made in the prior artconcerning the usefulness of this polycarbonate as a co-monomer forpolymaleimides.

In one embodiment of the present invention D is not a polycarbonate.

Interestingly, while U.S. Pat. No. 4,789,704 discloses resins comprisedof bismaleimides and alkenylphenoxy ethers which are based onpolyaddition products of polyfunctional epoxy resins and o-allylphenoland/or eugenol, thus bearing some structural resemblance to theco-monomers disclosed under the present invention, theseallylphenoxy-substituted epoxies yield mixtures with bismaleimides thatare slow curing therefore requiring extended cure times.

The key raw material for the synthesis of the presenttrans-2-Ethoxy-5-(1-propenyl)phenoxy-substituted compounds of formula(I) is trans (E)-2-Ethoxy-5-(1-propenyl)phenol, which is commerciallyavailable. Due to enantiomeric purity (trans (E) configuration) of the(1-propenyl) group in this molecule the compounds of the presentinvention according to formula (I) do not contain any cis (Z)-isomers.The Diels-Alder copolymerisation of the trans (E)-propenylphenoxycompounds of the present invention with polymaleimides is fast, thusallowing formulation of fast curing polymaleimide/co-monomer systemswhich are desirable for a number of technical applications.

In preferred embodiments of the present invention D in formula (I) is adifunctional group selected from the following:

-   -   (a) alkylene or alkenylene group with 2 to 12 carbon atoms;    -   (b) cycloalkylene group with 5 or 6 carbon atoms;    -   (c) heterocyclic group with 3 to 5 carbon atoms and at least one        nitrogen sulfur or oxygen atom in the heterocyclic ring;    -   (d) mono- or dicarbocyclic group;    -   (e) bridged multicyclic group consisting of at least two groups        selected from the following: monocarbocyclic aromatic groups,        dicarbocyclic aromatic groups, cycloalkylene groups; wherein        these groups are linked to each other by direct carbon-carbon        bonds or by divalent groups; wherein preferably the divalent        groups are selected from the following: oxy-group, thio-group,        alkylene-group with 1 to 3 carbon atoms, sulfone-group,        methanone-group;    -   (f) one of the groups of the following structures

-   -   wherein AR¹, AR², AR³, AR⁴, AR⁵ and AR⁶ are independently        difunctional aliphatic or aromatic residues;    -   and wherein n is an integer selected in the range from 2 to 100        and represents the number of repeating structural units in the        polymer backbone;    -   (g) group of the following structure

-   -   wherein R²⁶ is a monofunctional group selected from the        following:    -   (1) alkyl or alkenyl group with 2 to 12 carbon atoms,    -   (2) cycloalkyl group with 5 or 6 carbon atoms,    -   (3) aryl group with 6 to 12 carbon atoms,    -   (4) [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-group.

In further preferred embodiments of the present invention D in formula(I) is a difunctional group selected from the following:

-   -   wherein n is an integer selected in the range from 2 to 100 and        represents the number of repeating structural units in the        polymer backbone.

Curable Compositions of the Invention

In another aspect the present invention further relates to curablecompositions comprising:

-   -   i. at least one        [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compound        according to formula (I)

-   -   -   wherein        -   D is an x-functional group; and        -   x is an integer ≧2; and

    -   ii. at least one polyimide of formula (II)

-   -   wherein    -   B is a difunctional group containing a carbon-carbon double        bond, and    -   A is a y-functional group; and    -   y is an integer ≧2.

In preferred curable compositions of the present invention D in formula(I) is a difunctional group selected from the following:

-   -   (a) alkylene or alkenylene group with 2 to 12 carbon atoms;    -   (b) cycloalkylene group with 5 or 6 carbon atoms;    -   (c) heterocyclic group with 3 to 5 carbon atoms and at least one        nitrogen sulfur or oxygen atom in the heterocyclic ring;    -   (d) mono- or dicarbocyclic group;    -   (e) bridged multicyclic group consisting of at least two groups        selected from the following: monocarbocyclic aromatic groups,        dicarbocyclic aromatic groups, cycloalkylene groups; wherein        these groups are linked to each other by direct carbon-carbon        bonds or by divalent groups; wherein preferably the divalent        groups are selected from the following: oxy-group, thio-group,        alkylene-group with 1 to 3 carbon atoms, sulfone-group,        methanone-group;    -   (f) one of the groups of the following structures

-   -   wherein AR¹, AR², AR³, AR⁴, AR⁵ and AR⁶ are independently        difunctional aliphatic or aromatic residues;    -   and wherein n is an integer selected in the range from 2 to 100        and represents the number of repeating structural units in the        polymer backbone;    -   (g) group of the following structure

-   -   wherein R²⁶ is a monofunctional group selected from the        following:    -   (1) alkyl or alkenyl group with 2 to 12 carbon atoms,    -   (2) cycloalkyl group with 5 or 6 carbon atoms,    -   (3) aryl group with 6 to 12 carbon atoms,    -   (4) [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-group.

In further preferred curable compositions of the present invention D informula (I) is a difunctional group selected from the following:

-   -   wherein n is an integer selected in the range from 2 to 100 and        represents the number of repeating structural units in the        polymer backbone.

In preferred curable compositions of the present invention they-functional group A in the polyimide according to formula (II), isselected from the following difunctional groups:

-   -   a) alkylene group with 2 to 12 carbon atoms;    -   b) cycloalkylene group with 5 to 6 carbon atoms;    -   c) heterocyclic group with 4 to 5 carbon atoms and at least one        nitrogen, oxygen, or sulphur atom in the ring;    -   d) mono- or dicarbocyclic group;    -   e) bridged multicyclic group consisting of at least two groups        selected from the following: monocarbocyclic aromatic groups,        dicarbocyclic aromatic groups, cycloalkylene groups; wherein        these groups are linked to each other by direct carbon-carbon        bonds or by divalent groups; wherein preferably the divalent        groups are selected from the following: oxy-group, thio-group,        alkylene-group with 1 to 3 carbon atoms, sulfone-group,        methanone-group, or one of the following groups

-   -   -   wherein R¹, R², R³, R⁴, R⁵, R⁶ are independently alkyl            groups with 1 to 6 carbon atoms; and        -   R⁷ and R⁸ are independently alkylene groups with 1 to 6            carbon atoms;

    -   f) group defined by formula (III)

-   -   -   wherein R⁹ is one of the following groups

In preferred curable compositions of the present invention B in thepolyimide according to formula (II), is selected from the followingdifunctional groups:

In further preferred curable compositions of the present invention thepolyimide according to formula (II) is selected from the following:

4,4′-bismaleimidodiphenylmethane,bis(3-methyl-5-ethyl-4-maleimidophenyl)methane,bis(3,5-dimethyl-4-maleimidophenyl)methane,4,4′-bismaleimidodiphenylether, 4,4′-bismaleimidodiphenylsulfone,3,3′-bismaleimidodiphenylsulfone, bismaleimidodiphenylindane,2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene,1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene,1,4-bismaleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane,1,6-bismaleimido-(2,2,4-trimethyl)hexane,1,6-bismaleimido-(2,4,4-trimethyl)hexane,1,4-bis(maleimidomethyl)cyclohexane,1,3-bis(maleimidomethyl)cyclohexane,1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene,1,4-bis(maleimidomethyl)benzene.

In further preferred curable compositions of the present invention D informula (I) is a difunctional group selected from the following:

-   -   wherein n is an integer selected in the range from 2 to 100 and        represents the number of repeating structural units in the        polymer backbone.    -   and the polyimide according to formula (II) is selected from the        following:    -   4,4′-bismaleimidodiphenylmethane,        bis(3-methyl-5-ethyl-4-maleimidophenyl)methane,        bis(3,5-dimethyl-4-maleimidophenyl)methane,        4,4′-bismaleimidodiphenylether,        4,4′-bismaleimidodiphenylsulfone,        3,3′-bismaleimidodiphenylsulfone, bismaleimidodiphenylindane,        2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene,        1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene,        1,4-bismaleimidobenzene, 1,2-bismaleimidoethane,        1,6-bismaleimidohexane,        1,6-bismaleimido-(2,2,4-trimethyl)hexane,        1,6-bismaleimido-(2,4,4-trimethyl)hexane,        1,4-bis(maleimidomethyl)cyclohexane,        1,3-bis(maleimidomethyl)cyclohexane,        1,4-bismaleimidodicyclohexylmethane,        1,3-bis(maleimidomethyl)benzene,        1,4-bis(maleimidomethyl)benzene.

In another embodiment the present invention further relates to curablecompositions as defined above further comprising one or more cureinhibitors to retard the polymerisation reaction, thus modifyingprocessability and storage stability of the compositions andintermediate products, such as prepregs, moulding compounds and resinsolutions. Suitable cure inhibitors are Hydroquinone,1,4-Naphthoquinone, lonole and phenothiazine which are used atconcentrations between 0.1 wt % and 2.0 wt %, based on the total weightof the composition. It is advantageous to dissolve the inhibitor in oneof the components prior to the preparation of the mixture.

In another embodiment the present invention further relates to curablecompositions as defined above further comprising one or more cureaccelerators in order to accelerate the curing process. Typically cureaccelerators are added in an amount of 0.01 wt % to 5 wt %, preferablyin an amount of 0.1 wt % to 2 wt % based on the total weight of thecurable composition. Suitable cure accelerators include ionic and freeradical polymerization catalysts. Examples for free radicalpolymerization catalysts include (a) organic peroxides such asditertiary butyl peroxide, diamylperoxide and t-butylperbenzoate and (b)azo compounds such as azobisisobutyronitrile. Examples of ioniccatalysts are alkali metal compounds, tertiary amines such astriethylamine, dimethylbenzylamine, dimethylaniline, azabicyclooctane,heterocyclic amines such as quinoline, N-methylmorpholine,methylimidazole and phenylimidazole and phosphorous compounds such astriphenylphosphine and quaternary phosphonium halides. The cureaccelerators can be admixed with the components of the curablecomposition or may be added during the production of the prepolymerseither by a powder blending process or by a solvent blending process.

Curable Compositions Comprising a Secondary Co-Monomer Component

In another aspect the present invention further relates to curablecompositions comprising in addition to the at least one[2-ethoxy-5-(trans-1-propen-1-yl)phenoxy]-terminated compound accordingto formula (I) as defined above and the at least one polyimide offormula (II) as defined above, a secondary co-monomer component, whichconsists of one or a combination of at least two co-monomers selectedfrom the following: alkenylphenol, alkenylphenyl ether, alkenyl phenolether, polyamine, aminophenol, aminoacid hydrazide, cyanate ester,diallyl phthalate, triallyl isocyanurate, triallyl cyanurate, styrene,divinylbenzene, wherein the secondary co-monomer component representsbetween 1 wt % and 30 wt % of the total composition.

These secondary co-monomers may act as diluents for the compositions ofthe invention modifying their viscosity and/or processability. Thesecondary co-monomers may also act as cure accelerators or as cureretardants in the compositions of the invention.

Preferably the secondary co-monomer component consists of one or acombination of at least two co-monomers selected from the following:

(a) a compound of formula (IV)

-   -   wherein    -   R¹⁰ is a difunctional group, and    -   R¹¹ and R¹² are independently alkenyl groups with 2 to 6 carbon        atoms;

(b) a compound of formula (V)

-   -   wherein    -   R¹³ is a difunctional group, and    -   R¹⁴ and R¹⁵ are independently alkenyl groups with 2 to 6 carbon        atoms;

(c) a compound of formula (VI)

-   -   wherein    -   R¹⁶ is a difunctional group, and    -   R¹⁷ and R¹⁸ are independently alkenyl groups with 2 to 6 carbon        atoms;

(d) a compound of formula (VII)

-   -   wherein    -   R¹⁹ is a difunctional group, and    -   R²⁰ and R²¹ are independently alkenyl groups with 2 to 6 carbon        atoms;

(e) a compound of formula (VIII)

-   -   wherein    -   R²² is a y′-functional group, and    -   R²³ is an alkenyl group with 2 to 6 carbon atoms, and    -   y′ is an integer ≧2;

(f) a compound of formula (IX)

-   -   wherein    -   R²⁴ is a y″-functional group, and    -   R²⁵ is alkenyl group with 2 to 6 carbon atoms, and    -   y″ is an integer ≧2.

Preferably residues R¹⁰ in formula IV and R¹³ in formula V are selectedfrom the following groups:

-   -   and residues R¹⁶ in formula VI and R¹⁹ in formula VII are        selected from the following groups

-   -   and residues R²² in formula VIII and R²⁴ in formula IX are        difunctional groups selected from the following groups

-   -   and residues R²³ in formula VIII and R²⁵ in formula IX are        1-propen-1-yl or 2-propen-1-yl groups.

Preferably, the secondary co-monomer component consists of one or acombination of at least two co-monomers selected from the following:

2,2′-diallylbisphenol-A, bisphenol-A diallyl ether,bis(o-propenylphenoxy)benzophenone, m-aminobenzhydrazide, bisphenol-Adicyanate ester, diallyl phthalate, triallyl isocyanurate, triallylcyanurate, styrene, divinylbenzene.

Synthesis of Compounds According to Formula (I)

The [2-ethoxy-5-trans-(1-propen-1-yl)phenoxy]-substituted compoundsaccording to formula (I) can be synthesized by a variety of well knownchemical reactions from trans (E)-2-Ethoxy-5-(1-propenyl)phenol(Vanitrope) and appropriate polyfunctional, preferably difunctional,starting materials.

Compounds according to formula (I) wherein D represents a divalent groupselected from the following:

-   -   (a) alkylene or alkenylene group with 2 to 12 carbon atoms;    -   (b) cycloalkylene group with 5 or 6 carbon atoms;    -   (c) heterocyclic group with 3 to 5 carbon atoms and at least one        nitrogen sulfur or oxygen atom in the heterocyclic ring;    -   (d) mono- or dicarbocyclic group;    -   (e) bridged multicyclic group consisting of at least two groups        selected from the following: monocarbocyclic aromatic groups,        dicarbocyclic aromatic groups, cycloalkylene groups; wherein        these groups are linked to each other by direct carbon-carbon        bonds or by divalent groups; wherein preferably the divalent        groups are selected from the following: oxy-group, thio-group,        alkylene-group with 1 to 3 carbon atoms, sulfone-group,        methanone-group;

are obtained by the reaction of 2-ethoxy-5-trans (1-propen-1-yl)phenol(Vanitrope) in the form of its sodium or potassium salt with thecorresponding dihalo compound, Hal-D-Hal, by use of the Williamson ethersynthesis route, or by a nucleophilic halodisplacement reaction.

A preferred group of target compounds (I) may be prepared by reaction ofVanitrope, in the form of its sodium or potassium salt, withα,ω-dihaloalkanes, in a neutral solvent at temperatures around 60°C.-80° C., to provide α,ω-bis(trans-2 ethoxy-5-(1-propenyl))alkanes.

Another group of compounds according to formula (I) may be prepared byreaction of Vanitrope with dihalobenzophenone at a temperature of 170°C.-190° C. in the presence of N-methylpyrrolidone as a solvent and acatalyst, for example potassium carbonate. The synthesis may be modifiedsuch that dihalobenzophenone is reacted with a bisphenol, resorcinol orhydroquinone or bisphenol-A for example, to form a halo-terminatedpolyetherketone which is then endcapped with Vanitrope.4,4′-dichlorodiphenylsulfone may be used instead of dihalobenzophenonein the syntheses to provide the corresponding4,4′-bis(2-ethoxy-5-trans-(1-propen-1-yl)phenoxy)diphenylsulfone or thecorresponding Vanitrope-endcapped polyethersulfone.

Compounds according to formula (I) wherein D represents one of thefollowing structures

wherein n is an integer selected in the range from 2 to 100 andrepresents the number of repeating structural units in the polymerbackbone, and wherein AR¹ and AR² are independently difunctionalaliphatic or aromatic residues, can be synthesized from thecorresponding dicarboxylic acids and Vanitrope by an esterificationreaction. Vanitrope terminated polyesters can also be obtained fromcarboxyterminated polyesters and Vanitrope through esterification.

Compounds according to formula (I) wherein D represents one of thefollowing structures

wherein AR³ is a difunctional aliphatic or aromatic residue, can beprepared by the fusion reaction of epoxy compounds with Vanitrope attemperatures between 80° C. and 150° C. in the presence of a catalystsuch as triphenylphosphine or alkyltriphenylphosphonium halides. Thereaction may be performed in the presence of an organic solvent or inthe absence of a diluent. The molar ratio between Vanitrope andpolyepoxy compound may be such that no residual epoxy groups remain atthe end of the reaction or the amount of Vanitrope may be lower thanstoichiometric to provide a compound containing free unreacted epoxygroups. The preferred epoxy compounds to be used in this synthesis are1,3-bisglycidylresorcinol, 4,4′-bisglycidylbisphenol-A,4,4′-bisgycidylbisphenol-F and any other glycidylethers of bisphenols orpolyphenols such as phenolnovolaks or bisphenolnovolaks. Alsotriglycidy-p-aminophenol or tetraglycidymethylene dianiline are suitablestarting materials. High molecular weight phenoxy resins synthesizedfrom polyepoxy resin and bisphenols with terminal epoxy groups aresuitable epoxy compounds for Vanitrope terminated phenoxy resins.

Compounds according to formula (I) wherein D represents one of thefollowing structures

wherein n is an integer selected in the range from 2 to 100 andrepresents the number of repeating structural units in the polymerbackbone, can be synthesized by reaction of Vanitrope with phosgene toprovides the Vanitrope carbonate, with bisphenol-A bischloroformiate toprovide Vanitrope/Bisphenol-A carbonate, or with achlorofomiate-terminated polycarbonate to a Vanitrope terminatedpolycarbonate.

Compounds according to formula (I) wherein D represents one of thefollowing structures

wherein n is an integer selected in the range from 2 to 100 andrepresents the number of repeating structural units in the polymerbackbone, and wherein AR⁴ and AR⁶ are independently difunctionalaliphatic or aromatic residues, can be synthesized by reaction ofVanitrope with a bis-isocyanate or an isocyanate terminatedpolyurethane. A wide variety of organic polyisocyanates may be employedto react with the Vanitrope including aromatic, aliphatic andcycloaliphatic polyisocyanates. Representative compounds include toluene2,6-diisocyanate, toluene 2,4-diisocyanate, m-phenylene diisocyanate,4,4′-bisphenylene diisocyanate, 1,5-naphthalene diisocyanate,4,4′bisisocyanatodiphenylmethane, 4,4′-bisisocyanatodiphenylether,1,6-bisisocyanatohexane, 2,2,4-trimethyl hexamethylene diisocyanate,isophorone diisocyanate and any other polyisocyanate. Very advantageouspolyisocyanates to be reacted with Vanitrope are those obtained by thereaction of a bis-isocyanate with polyalkylene ether glycols, providingisocyanate terminated macropolyisocyanates. Products based onpolypropylene ether glycols are of particular interest because of theirlow moisture absorption.

Processes for the Manufacture of Curable Compositions of the Invention

In one aspect, the present invention further relates to processes forthe manufacture of curable compositions according to the invention,comprising the step of blending the components of the composition usinga powder-, melt-, solvent-assisted or other blending process resultingin solid, low-melting, or tacky curable compositions.

Melt Blending Process

In one aspect, the present invention relates to processes for themanufacture of curable compositions of the invention, comprising thestep of:

blending the components of a composition comprising a co-monomercomponent of the invention and a polyimide component as defined above ata temperature ranging from 70° C. to 250° C. to obtain curablecompositions as low melting low viscosity masses (resins).

In the practice of this method, the blending temperatures may be variedover a relatively wide range. In one embodiment, the method is carriedout at temperatures from 90° C. to 170° C., preferably from 100° C. to160° C.

Solution Blending Process

In one aspect, the present invention relates to processes for themanufacture of curable compositions of the invention, comprising thestep of:

dissolving the components of a composition comprising a co-monomercomponent of the invention and a polyimide component as defined above,in a solvent or diluent, and

stripping off the solvent or diluent, to obtain a curable composition asa solvent-free, low melting, low viscosity mass (resin).

In one embodiment, the co-monomer component of the invention and thepolyimide component as defined above are dissolved in the solvent atelevated temperature.

Suitable solvents and diluents are all customary inert organic solvents.They include but are not limited to ketones such as acetone,methylethylketone, cyclohexanone; glycol ethers such as methyl glycol,methyl glycol acetate, propylene glycol monomethyl ether (methylproxitol), methyl proxitol acetate, diethylene glycol, and diethyleneglycol monomethyl ether; toluene and xylene, preferably in combinationwith 1,3-dioxolane as a co-solvent.

In a preferred embodiment, the solvent is 1,3-dioxolane or a1,3-dioxolane-containing solvent.

In one embodiment, the amount of 1,3-dioxolane in the solvent mixtureranges from 20 wt % to 80 wt %, e.g. from 30 wt % to 70 wt % or from 40wt % to 60 wt %.

In the practice of the processes for the manufacture of the curablecomposition, i.e. in the melt process and in the solution process, themolar ratio between the unsaturated imide groups and reactive alkenylgroups in the composition ranges from 1.0 to 0.1, e.g. from 1.0 to 0.2,from 1.0 to 0.3, from 1.0 to 0.4, from 1.0 to 0.5, from 1.0 to 0.6, from1.0 to 0.7 or from 1.0 to 0.8 in order to achieve the desired curekinetics.

Other Blending Processes

Preparation of the curable compositions of this invention can be carriedout without any diluent or solvent in that the components as powders,pastes or liquids are intimately mixed, if necessary at elevatedtemperature, to obtain a homogeneous blend of the monomers or aprepolymer depending on the duration of the temperature treatment. Thisprocess cannot be scaled up to reasonable volumes due to the highreactivity of the BMI/Vanitrope type co-monomer mixture. An extruderprocess may be used to control and set the required melting temperature,to provide the necessary temperature for prepolymerization in thereaction zone and to set the time at temperature by the throughput. Theextrudate, after cooling, may be a hot melt product or a solidified meltwhich can be milled to a resin powder.

Storage Stable Mixtures

For many technical applications of the curable compositions it isadvantageous to retard polymerisation by the addition of reactioninhibitors in order to improve processability and storage stabilitybefore use. Suitable reaction inhibitors are hydroquinone,1,4-naphthoquinone and phenothiazine which are used at concentrationsbetween 0.1 wt % and 2.0 wt %, based on the total weight of thecomposition. It is advantageous to dissolve the inhibitor in one of thecomponents prior to the preparation of the composition.

Compositions Comprising a Secondary Co-Monomer Component

In many cases the curable compositions of the present invention may beprocessed from the melt. In order to reduce melt viscosity and improvepot life of the resin a secondary co-monomer component may be added,which consists of one or more co-monomers selected from the following:alkenylphenol, alkenylphenyl ether, alkenyl phenol ether, polyamine,aminophenol, aminoacid hydrazide, cyanate ester, diallyl phthalate,triallyl isocyanurate, triallyl cyanurate, styrene, divinylbenzene,wherein the secondary co-monomer component represents between 1 wt % and30 wt % of the total composition. Of these, allyl-type secondaryco-monomer components such as diallylbisphenol-A, bisphenol-Adiallylether, diallylphthalate, triallylisocyanurate andtriallylcyanurate when added to the curable composition slow downpolymerisation kinetics and therefore widen the processing window.Secondary co-monomer components like styrene or divinylbenzene are veryeffective in concentrations between 10 wt % and 20 wt % but acceleratepolymersation kinetics, providing faster curing resins and loweringtheir polymerisation temperature. Therefore, secondary co-monomercomponents are an additional tool to modify cure velocity of the curablecompositions of the invention. In cases where such secondary co-monomercomponents are used it is advantageous to first blend the[2-ethoxy-5-trans-(1-propen-1-yl)phenoxy]-substituted compound (I) withthe secondary co-monomer component in the required proportion and then,in a second step, dissolve the polyimide part of the mixture in thisblend, if nessecary at elevated temperature.

Compositions Comprising Thermoplastic Toughening Modifier

Curable compositions of the present invention may further include from 0wt % to about 30 wt %, based on the total weight of the composition, ofa thermoplastic polymer such as, for example, a polyaryl ether, apolyaryl sulfone, a polyarylate, a polyamide, a polyaryl ketone, apolyimide, a polyimide-ether, a polyolefin, an ABS resin, a polydiene ordiene copolymer or mixtures thereof.

Thermoplastics such as polysulfons and phenoxy resins are particularlymiscible with the curable compositions of the present invention, and maybe used to adjust resin viscosity and control flow during cure.Thermoplastic polymers may also be added to improve the fracturetoughness.

Thermoplastic polymers can be added to the curable compositions as finepowders, or may be dissoved in either the[2-ethoxy-5-trans-(1-propen-1-yl)phenoxy]-substituted compound (I) or asecondary co-monomer component.

The curable compositions of the invention can be isolated by customarytechniques and processes (cf. e.g. examples section).

Pre-Polymers of Curable Compositions of the Invention and Processes fortheir Manufacture

In one aspect the present invention relates to the use of a curablecomposition as defined above for the preparation of a prepolymer.

It has been found that the curable compositions of the invention areuseful for the preparation of partially cross-linked products (i.e.prepolymers). Prepolymers are prepared by heating curable compositionsas defined above to temperatures of 80° C. to 350° C., preferably to100° C. to 250° C. for a time sufficient to obtain a prepolymer which isstill formable upon applying heat and/or pressure. Optionally this isperformed in the presence of a cure catalyst or cure stabilizer.

Cure Accelerators

For some applications of the curable compositions of the presentinvention it is advantageous to accelerate the curing process by addingcatalysts, typically in an amount of 0.01 wt % to 5 wt %, preferably inan amount of 0.1 wt % to 2 wt % based on the total weight of the curablecomposition. Suitable catalysts include ionic and free radicalpolymerization catalysts. Examples for free radical polymerizationcatalysts include (a) organic peroxides such as ditertiary butylperoxide, diamylperoxide and t-butylperbenzoate and (b) azo compoundssuch as azobisisobutyronitrile. Examples of ionic catalysts are alkalimetal compounds, tertiary amines such as triethylamine,dimethylbenzylamine, dimethylaniline, azabicyclooctane, heterocyclicamines such as quinoline, N-methylmorpholine, methylimidazole andphenylimidazole and phosphorous compounds such as triphenylphosphine andquaternary phosphonium halides. The catalysts can be admixed with thecomponents of the curable composition or may be added during theproduction of the prepolymers either by a powder blending process or bya solvent blending process as described above.

In another aspect the present invention further comprises curablepre-polymers obtainable from curable compositions according to theinvention, by a process comprising the step of heating the curablecomposition to a temperature in the range of 50° C. to 250° C.,preferably to 70° C. to 170° C., for a time sufficient to obtain apre-polymer, which is still formable upon the application of heat and/orpressure.

If the method is carried out in the presence of a solvent, high boilingpoint polar solvents such as dimethylformamide, dimethylacetamide,N-methylpyrrolidone, and butyrolactone can in principle be used.However, the use of such solvents generally yields prepolymers with highcontents of residual solvents.

If the method is carried out in the presence of a solvent, in oneembodiment low boiling solvent mixtures containing 1,3-dioxolane may beused. These preferably include, but are not limited to, solvent mixturesof 1,3-dioxolane with ketones such as acetone, methylethylketone,cyclohexanone or glycol ethers such as ethylene glycol ether, propyleneglycol ether, butylene glycol ether and their acetates.

Due to the low boiling point of solvent mixtures comprising1,3-dioxolane and the above-identified solvents, such solvent mixturesare useful for the preparation of solvent free prepolymers. Further, theso obtained prepolymers can be processed to void-free fiber-reinforcedcomposites.

In one embodiment, the solvent mixture comprises up to 50 wt %,preferably up to 40 wt % of ketones such as acetone, methylethylketone,cyclohexanone, or glycol ethers such as ethylene glycol ether, propyleneglycol ether, butylene glycol ether, and their acetates based on thetotal weight of the solvent mixture.

In one embodiment, a solution of the curable composition of theinvention comprises from 30 wt % to 70 wt %, preferably from 40 wt % to60 wt % of solvent, e.g. of 1,3-dioxolane, or solvent mixturescomprising 1,3-dioloxane, and the above-identified solvents. Suchconcentrations are typically used in industrial dip coating processes.

The prepolymers of the curable composition of the invention can beisolated by generally customary processes, e.g. by evaporation of thesolvent if the subsequent use is solvent free.

The prepolymers which are obtained according to the method of theinvention are still soluble in selected organic solvents. Further, theprepolymers of the invention are still fusible and formable upon theapplication of heat and/or pressure.

In another aspect, the present invention relates to a curable prepolymerobtainable according to a method as described above.

Crosslinked Polymers of the Curable Compositions of the Invention andProcesses for their Manufacture

In one aspect, the invention relates to the use of a curable compositionas defined above or of a prepolymer as defined above for the preparationof a crosslinked polymer.

It has been found that the curable compositions and curable prepolymersof the invention are useful for the preparation of crosslinked polymers.

In one aspect, the invention relates to a method for the preparation ofa crosslinked polymer comprising the step of:

-   -   heating a curable composition as defined above or a curable        prepolymer as defined above to a temperature ranging from 70° C.        to 280° C. for a time sufficient to complete cure.

In the practice of this method, the reaction temperatures may be variedover a relatively wide range. In one embodiment, the method is carriedout at temperatures from 80° C. to 270° C., more preferably from 90° C.to 260° C., most preferably from 100° C. to 250° C.

In another aspect the present invention further comprises crosslinkedpolymers obtainable from the curable compositions according to theinvention by a process comprising the step of heating the curablecomposition to a temperature in the range of 70° C. to 280° C. for atime sufficient to obtain a polymer.

The conversion may take place with simultaneous shaping under pressureto obtain mouldings, laminates, adhesive bonds, and foams.

For these applications, it is possible to admix the curable compositionwith additives such as fillers, pigments, colorants, and flameretardants. Suitable fillers are glass- or carbon fibers, graphite,quartz, metal powders, and metal oxides. Mould release agents such assilicone oil, waxes, Zn and K-stearates may also be added.

In another aspect, the present invention relates to mouldings,laminates, adhesive bonds, and foams obtainable by processing of thecurable composition and curable prepolymers of the invention.

Composite Materials of the Invention and Processes for their Manufacture

It has been found that curable compositions and prepolymers of theinvention are useful for the preparation of composite materials.

Mixtures Containing Particulate Fillers

The curable compositions of the present invention can be processed byknown methods of the powder moulding industry for producing mouldings,with curing taking place with simultaneous shaping under pressure. Forthese applications the curable compositions are admixed with additivessuch as fillers, colorants and flame retardants. Ideal fillers forexample are short glass fibers, short carbon fibers or aramid fibers,particulate fillers such as quartz, silica, ceramics, metal powders andcarbon powder. Depending on the technical application of the mouldedarticle two or more different fillers may be used at the same time.

Applications

One of the preferred uses of the curable compositions of the presentinvention is as binders for fiber composites. For this applicationfibers such as glass, carbon or aramid in the form of rovings, fabrics,short fiber mats, or felts are impregnated with the curable composition,employing a solution of the said curable composition to impregnate saidreinforcements. After drying off the solvent a prepreg is left, which inthe second phase may be cured at a temperature between 180° C. and 350°C., optionally under pressure.

Melt Prepregs

A preferred application oft the curable compositions of the presentinvention is as hot-melt resins for fiber-reinforced composites. Inorder to obtain such fiber-reinforced composites the curablecompositions are processed as hot melts to a resin film on a carrierfoil, subsequently fibers, in the form of rovings or fabrics, arepressed into the molten resin film to form a prepreg. For this processcurable compositions, which have a low viscosity at low temperature areadvantageous in order to provide adequate impregnation of fiber rovingsor fabric.

Laminates

One of the preferred applications of the curable compositions of thepresent invention is as resins for fiber laminates. Prepregsmanufactured by either the solvent/solution- or the hot-melt processfrom glass-, carbon- or aramid fibers, in the form of fabriques orrovings, are stacked to provide a prepreg laminate, which subsequentlyis cured under pressure or in a vacuum bag at a temperature between 150°C. and 280° C. preferably between 170° C. and 260° C.

In one aspect, thus, the invention relates to a method for thepreparation of a composite material comprising the steps of:

applying or blending a curable composition in form of alow-viscosity-melt stable resin obtainable according to the method asdefined above, or a prepolymer as defined above, onto or with a fibrousor particulate reinforcement (filler); and subsequent curing.

In one embodiment, the curable composition or the prepolymer as definedabove is applied onto or blended with a fibrous or particulatereinforcement (filler) with the use of standard processing techniques,e.g with the use of the hot melt or solution-based prepregging, resintransfer moulding (RTM), resin infusion moulding (RIM), filament winding(FW) or compounding techniques.

Curing may be carried out at temperatures ranging from 70° C. to 280°C., preferably at temperatures ranging from 80° C. to 270° C., morepreferably at temperatures ranging from 90° C. to 260° C., mostpreferably at temperatures ranging from 100° C. to 250° C. for a timesufficient to complete cure.

In another aspect the present invention further comprises processes forthe manufacture of composite materials comprising the steps of combininga curable composition according to the invention or a curablepre-polymer according to the invention, with a fibrous or particulatereinforcement, and curing the resultant product.

In one embodiment, the composite material is a fiber-reinforcedcomposite.

In one embodiment, the composite material is a particulate-filledcomposite.

In one aspect, the present invention relates to a method for thepreparation of a composite material comprising the steps of:

-   (a) preparing a curable composition or a prepolymer thereof as    defined above,-   (b) applying a curable composition or a prepolymer thereof as    defined above onto a fibrous reinforcement or blending with a    particulate filler,-   (c) curing the curable composition or prepolymer thereof as defined    above at a temperature ranging from 70° C. to 280° C. for a time    sufficient to complete cure, and-   (d) simultaneously applying pressure to obtain the composite    material.

Process step c) may be carried out at temperatures ranging from 70° C.to 280° C., preferably at temperatures ranging from 80° C. to 270° C.,more preferably at temperatures ranging from 90° C. to 260° C., mostpreferably at temperatures ranging from 100° C. to 250° C. for a timesufficient to complete cure.

In the practice of process step c) the conversion of the curablecompositions or prepolymers of the invention into the crosslinked(cured) polymer may be carried out, in the presence of a curing catalystas defined above.

In the practice of process step d) shaping under pressure is performedto obtain the composites of the invention. Process steps c) and d) arecarried out simultaneously.

A preferred application of the curable compositions of the invention isresins for fiber-reinforced composites. In order to obtain such fibercomposites the curable compositions of the invention are processed ashot melts to resin film on a carrier foil, which is subsequently used toprepare prepolymers by pressing fibers in the form of rovings or fabricsinto the resin film. For this process curable compositions, which have alow viscosity at low temperature are advantageous in order to provideadequate impregnation of fiber rowings or fabric.

In one aspect the present invention comprises composite materialsobtainable by a process according to the invention.

Definitions

As used herein, including the accompanying claims, the terms, which arecollectively used, have the following meanings.

As used herein, the term “curable” means that an original compound(s) ormixture material(s) can be transformed into a solid, substantiallynon-flowing material by means of chemical reaction, crosslinking,radiation crosslinking or the like.

As used herein, the term “mixture” means a physical or mechanicalaggregation or a combination of two or more individual, chemicallydistinct compounds that are not chemically united.

As used herein, the term “polyimide component” means one polyimide or amixture of two or more polyimides, preferably one polyimide or a mixtureof two to four polyimides.

As used herein, the term “co-monomer” means a compound that can undergopolymerization or copolymerization, thereby contributing constitutionalunits to the essential structure of a polymer.

As used herein, the term “co-monomer component” means one co-monomer ora mixture of two or more co-monomers, preferably one co-monomer or amixture of two to four co-monomers.

As used herein, the term “alkenylphenol” means organic compoundscomprising at least one alkenyl-substituted phenol group. The term“alkenylphenol” comprises alkenylphenols, wherein two phenol groups arebridged via a difunctional group, e.g. alkenylbisphenols. Examplesinclude 2,2′-diallyl-bisphenol A.

As used herein, the term “alkenylphenyl ether” means organic compoundscomprising at least one alkenyloxyphenyl group, i.e. an ether groupwherein the ether oxygen atom is connected on one hand to an alkenylresidue and on the other hand to a phenyl residue. The term“alkenylphenyl ether” comprises alkenylphenyl ethers, wherein two phenylgroups are bridged by a difunctional group, e.g. alkenylbisphenol ether.Examples include diallyl ether of bisphenol A.

As used herein, the term “alkenylphenol ether” means organic compoundscomprising at least one alkenylphenoxy group, e.g. an ether groupwherein the ether oxygen atom is connected on one hand to analkenylphenyl group and on the other hand to a an alkyl or an arylgroup. The term “alkenylphenol ether” comprises organic compounds,wherein two alkenylphenoxy groups are bridged by a difunctional group,e.g. by an aromatic group such as a benzophenone group. Examples includebis-(o-propenylphenoxy)benzophenone.

As used herein, the term “polyamine” means an organic compound havingtwo or more primary amino groups —NH₂. Examples include, but are notlimited to 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone,3,3′-diaminodiphenylsulfone, diaminodiphenylindane, m-phenylenediamine,p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene,m-xylylenediamine and aliphatic diamines such as ethylenediamine,hexamethylenediamine, trimethylhexamethylenediamine,1,12-diaminododecane.

As used herein, the term “aminophenol” means amino-substituted phenols.Examples include m-aminophenol and p-aminophenol.

As used herein, the term “amino acid hydrazides” means any hydrazides ofamino acids. Examples include m-aminobenzhydrazide andp-aminobenzhydrazide.

As used herein, the term “cyanate ester” means a bisphenol orpolyphenol, e.g. novolac, derivative, in which the hydrogen atom of thephenolic OH group is substituted by a cyano-group, resulting in an —OCNgroup. Examples include bisphenol A dicyanate ester, commerciallyavailable as, e.g. Primaset BADCy from Lonza or AroCy B-10 fromHuntsman, as well as other Primaset or AroCy types, e.g.bis(3,5-dimethyl-4-cyanatophenyl)methane (AroCy M-10),1,1-bis(4-cyanatophenyl)ethane (AroCy L-10),2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane (AroCy F-10),1,3-bis(1-(4-cyanatophenyl)-1-methylethylidene)benzene (AroCy XU-366),di(4-cyanatophenyl)thioether (AroCy RDX-80371; AroCy T-10),bis(4-cyanatophenyl)dichloromethylidenemethane (AroCy RD98-228),bis(4-cyanatophenyl)octahydro-4,7-methanoindene (AroCy XU-71787.02L), aswell as bis(4-cyanatophenyl)methane,bis(3-methyl-4-cyanatophenyl)methane,bis(3-ethyl-4-cyanatophenyl)methane, di(4-cyanatophenyl)ether,4,4-dicyanatobiphenyl,1,4-bis(1-(4-cyanatophenyl)-1-methylethylidene)benzene, resorcinoldicyanate.

A preferred example is bisphenol A dicyanate ester.

Any bond intersected by a bracket indicates a bond that connects themoiety within the bracket to other moieties of the same compound. Forexample, in the group shown below the two bonds of the ethenyl groupintersected by the bracket on the right side connect this moiety toother moieties of the compound containing this ethenyl group.

As used herein, the term “halogen” means a fluorine, chlorine, bromineor iodine atom, preferably a fluorine or chlorine atom, more preferablya fluorine atom.

As used herein, “alkyl” means a straight-chain or branched alkyl group.The term “alkyl with n to m carbon atoms” means an alkyl group with n tom carbon atoms. If not denoted otherwise, “alkyl” means an alkyl with 1to 6 carbon atoms. In the context of the present invention, preferredalkyl groups are straight-chain or branched alkyl groups with 1 to 4carbon atoms. Examples of straight-chain and branched alkyl groupsinclude, but are not limited to methyl, ethyl, propyl, isopropyl, butyl,isobutyl, tert.-butyl, the isomeric pentyls, the isomeric hexyls,preferably methyl and ethyl and most preferred methyl.

As used herein, “alkylene” means a difunctional alkyl group. The term“alkylene with n to m carbon atoms” means an alkylene group with n to mcarbon atoms. If not denoted otherwise, “alkylene” means an alkylenewith 1 to 12 carbon atoms. In the context of the present invention,preferred alkylene groups are alkylene groups with 1 to 9 carbon atoms,more preferably from 1 to 6 carbon atoms. Examples include, but are notlimited to methylene, ethylene, propylene, butylene, hexamethylene and2,2,4-trimethylhexamethylene. Particularly preferred is2,2,4-trimethylhexamethylene.

As used herein, “alkenylene” means a difunctional alkenyl group. Theterm “alkenylene with n to m carbon atoms” means an alkenylene groupwith n to m carbon atoms. If not denoted otherwise, “alkenylene” meansan alkenylene with 2 to 12 carbon atoms. In the context of the presentinvention, preferred alkenylene groups are alkenylene groups with 2 to10 carbon atoms, more preferably from 2 to 6 carbon atoms. Examplesinclude, but are not limited to ethenylene, propenylene, and butenylene.Particularly preferred is ethenylene.

As used herein, “alkoxy” means a straight-chain or branched alkyl group,which is bonded to the compound via an oxygen atom (—O—). The term“alkoxy with n to m carbon atoms” means an alkoxy with n to m carbonatoms. If not denoted otherwise, “alkoxy” means a straight-chain orbranched alkyl group with 1 to 6 carbon atoms. In the context of thepresent invention, preferred alkoxy groups are straight-chain orbranched alkoxy groups with 1 to 4 carbon atoms.

As used herein, “alkenyl” means a straight-chain or branched hydrocarbongroup comprising a carbon-carbon double bond. The term “alkenyl with nto m carbon atoms” means an alkenyl with n to m carbon atoms. If notdenoted otherwise, “alkenyl” means a straight-chain or branchedhydrocarbon group comprising a carbon-carbon double bond in any desiredposition and 2 to 10 carbon atoms. In the context of the presentinvention, preferred alkenyl groups comprise a carbon-carbon double bondin any desired position and 2 to 6, more preferably 2 to 4 carbon atoms.Examples of alkenyl groups include, but are not limited to ethenyl,1-propenyl, 2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl andisobutenyl. Preferred examples are 1-propenyl and 2-propenyl.

As used herein the term “monocarbocyclic group” means a “monocarbocyclicaliphatic group” or a “monocarbocyclic aromatic group”.

As used herein the term “dicarbocyclic group” means a “dicarbocyclicaliphatic group” or a “dicarbocyclic aromatic group” group.

As used herein the term “monocarbocyclic aliphatic group” means acycloalkylene group.

As used herein, “cycloalkyl” means a monofunctional carbocyclicsaturated ring system. The term “cycloalkyl with n to m carbon atoms”means a cycloalkyl with n to m carbon atoms. If not denoted otherwise,“cycloalkyl” means a cycloalkyl group with 5 to 6 carbon atoms. Examplesof cycloalkyl groups include, but are not limited to cyclopropanyl,cyclobutanyl, cyclopentanyl, cyclohexanyl, cycloheptanyl orcyclooctanyl, preferably cyclopentanyl and cyclohexanyl.

As used herein, “cycloalkylene” means a difunctional carbocyclicsaturated ring system. The term “cycloalkylene with n to m carbon atoms”means a cycloalkylene with n to m carbon atoms. If not denotedotherwise, “cycloalkylene” means a cycloalkylene group with 3 to 8carbon atoms. In the context of the present invention preferredcycloalkylene groups are cycloalkylene groups with 5 to 7, morepreferably 5 or 6 carbon atoms. Examples include, but are not limited tocyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene,cycloheptylene or cyclooctylene, preferably cyclopentylene andcyclohexylene.

As used herein, “dicarbocyclic aliphatic group” means a difunctionalbicyclic condensed, bridged or fused saturated ring system. If notdenoted otherwise, “dicarbocyclic aliphatic group” means a difunctionalbicyclic condensed, bridged or fused saturated ring system with 9 to 20carbon atoms. Examples include, but are not limited to decalinyl,hydrindanyl and norbornyl.

As used herein, the term “mono- or dicarbocyclic aromatic group” means adifunctional mono- or dicyclic aromatic system, preferably with 6 to 12carbon atoms, preferably a monocyclic aromatic system. Examples include,but are not limited to, toluene, phenylene, naphthylene,tetrahydronaphthylene, indenylene, indanylene, pentalenylene,fluorenylene and the like, preferably toluene, phenylene or indanylene.

As used herein, the term “aryl” means a monofunctional mono- or dicyclicaromatic system, preferably with 6 to 12 carbon atoms, preferably amonocyclic aromatic system. Examples include, but are not limited to,toluyl, phenyl, naphthyl, tetrahydronaphthyl, indenyl, indanyl,pentalenyl, fluorenyl and the like, preferably toluyl, phenyl orindanyl.

As used herein, the term “heterocyclic group” means a “heterocyclicaliphatic group” or a “heterocyclic aromatic group”

As used herein, the term “heterocyclic aliphatic group” means adifunctional saturated ring system which, in addition to carbon atoms,comprises one, two or three atoms selected from nitrogen, oxygen and/orsulfur. Preferred heterocyclic aliphatic groups are those containing 3to 5 carbon atoms and one nitrogen, oxygen or sulfur atom.

As used herein, the term “heterocyclic aromatic group” means amonocyclic aromatic 5- or 6-membered ring, which comprises one, two orthree atoms selected from nitrogen, oxygen and/or sulfur, or a bicyclicaromatic group comprising two 5- or 6-membered rings, in which one orboth rings can contain one, two or three atoms selected from nitrogen,oxygen or sulfur. Examples include, but are not limited to pyridyl,pyrazinyl, pyrimidinyl, pyridazinyl, oxazolyl, oxydiazolyl, isoxazolyl,thiadiazolyl, tetrazolyl, pyrazolyl, imidazolyl, thiazolyl, thienyl,quinolinyl, isoquinolinyl, cinnolinyl, pyrazolo[1,5-a]pyridyl,imidazo[1,2-a]pyridyl, quinoxalinyl, benzothiazolyl, benzotriazolyl,indolyl, indazolyl.

As used herein the term “bridged multicyclic group” means a groupconsisting of at least two groups selected from the following:monocarbocyclic aromatic groups, dicarbocyclic aromatic groups,cycloalkylene groups; wherein these groups are linked to each other bydirect carbon-carbon bonds or by divalent groups.

Preferred divalent groups are oxy-group, thio-group, alkylene-group with1 to 3 carbon atoms, sulfone-group, methanone-group, and the followinggroups:

wherein R¹, R², R³, R⁴, R⁵, R⁶ are independently alkyl groups with 1 to6 carbon atoms; and

R⁷ and R⁸ are independently alkylene groups with 1 to 6 carbon atoms.

In one embodiment the term “bridged multicyclic group” means a groupconsisting of two monocarbocyclic aliphatic groups, which are linked toeach other by a direct carbon-carbon bond or by a divalent group such asoxy-group, thio-group, alkylene-group with 1 to 3 carbon atoms,sulfone-group, methanone-group, or one of the following groups:

wherein R¹, R², R³, R⁴, R⁵, R⁶ are independently alkyl groups with 1 to6 carbon atoms; and

R⁷ and R⁸ are independently alkylene groups with 1 to 6 carbon atoms.

In one embodiment the term “bridged multicyclic group” means a groupconsisting of two cyclohexylene groups, which are linked to each otherby a direct carbon-carbon bond or by a divalent group such as oxy-group,thio-group, alkylene-group with 1 to 3 carbon atoms, sulfone-group,methanone-group.

In one embodiment the term “bridged multicyclic group” means a groupconsisting of two monocarbocyclic aromatic groups, which are linked toeach other by a direct carbon-carbon bond or by a divalent group such asoxy-group, thio-group, alkylene-group with 1 to 3 carbon atoms,sulfone-group, methanone-group, or one of the following groups:

wherein R¹, R², R³, R⁴, R⁵, R⁶ are independently alkyl groups with 1 to6 carbon atoms; and

R⁷ and R⁸ are independently alkylene groups with 1 to 6 carbon atoms.

In one embodiment the term “bridged multicyclic group” means a groupconsisting of two phenylene groups, which are linked to each other by adirect carbon-carbon bond or by a divalent group such as oxy-group,thio-group, alkylene-group with 1 to 3 carbon atoms, sulfone-group,methanone-group.

As used herein, the addition of the terms “unsubstituted” or“substituted” means that the respective groups are unsubstituted orcarry from 1 to 4 substituents selected from the following: alkyl,alkoxy, halogen. Preferred substituents are methyl or ethyl.

As used herein, the terms “x-functional group”, “y-functional group”,“y′-functional group” and “y″-functional group” respectively, denote agroup, which is bonded to the remainder of the compound via x, y, y′, ory″ bond(s), respectively. Preferably, the “x-functional group”,“y-functional group”, “y′-functional group” and “y″-functional group” isa difunctional group, i.e. x, y, y′ and y″ are preferably 2.

As used herein, the term “difunctional group” means a group, which isbonded to the remainder of the compounds via two bonds. Difunctionalgroups include but are not limited to, difunctional aliphatic groups anddifunctional aromatic groups. Difunctional aliphatic groups include butare not limited to the following groups:

Difunctional aromatic groups include but are not limited to thefollowing groups:

Further difunctional groups include, but are not limited to thefollowing groups:

As used herein, the term “Glass transition temperature” or “Tg” meansthe temperature of reversible transition of an amorphous solid, e.g.polymer, between high elastic state and vitreous (glassy) state, whenthe polymer becomes brittle on cooling, or soft on heating. Morespecifically, it defines a pseudo second order phase transition, inwhich a supercooled melt yields, on cooling, a glassy structure andproperties similar to those of crystalline materials, e.g. of anisotropic solid material.

EXAMPLES

The following examples are intended to illustrate but not to limit theinvention.

I. Syntheses of Vanitrope-Terminated Compounds (I) Example 1 Synthesisof 4,4′-bis-[(2-ethoxy-5-(trans-1-propen-1-yl))phenoxy]benzophenone

To 141.8 g (0.65 mol) of 4,4′-difluorobenzophenone in 180 ml ofdimethylacetamide (DMAc), placed in a 1500 ml-flask fitted with astirrer, reflux condensor, and thermometer were added 129 g (0.93 mol)of potassium carbonate and the mixture was heated to 100° C. at whichtemperature was added a warm (60° C.) solution of 254.8 g (1.43 mols) ofvanitrope dissolved in 120 ml of DMAc within a few minutes. The mixturewas heated to 155° C. for 6 hours and subsequently cooled to 120° C. 600ml of 1-methoxy-2-propanol were added to the stirred solution andsubsequently 600 ml of water. The batch was cooled down to roomtemperature, the precipitate formed was filtered off and washed with amethanol/water mixture. The wet product was recrystallized from 1000 mlof 1-methoxy-2-propanol, filtered off and washed with 100 ml ofdiisopropylether. The fine crystalline, off-white product was dried at70° C. in a vacuum oven. Yield: 278.0 g (80%). Purity: 99.3% (HPLCarea-%). Melting point: 112° C.

Example 1a Synthesis of Vanitrope-Terminated Polyetheretherketone

72 g (0.33 mol) of 4,4′-difluorobenzophenone, 33.03 g (0.30 mol) ofresorcinol and 116.1 g (0.84 mol) of dry potassium carbonate togetherwith 200 ml of N-methylpyrolidone and 70 ml of toluene, were placed in a3-necked flask equipped with a stirrer, reflux condensor, and aDean-Stark trap, and were heated at 155° C. for 4 hours, after whichtime water was distilled off and separated by the Dean-Stark trap. Aftercooling down to 110° C., 10.51 g (0.06 mol) of vanitrope and 11.60 g(0,084 mol) of dry potassium carbonate were added. The reaction mixturewas then heated at 155° C. for 5 hours and subsequently heated at 180°C. for 2 hours. After cooling down to room temperature 1000 ml of a 1:1methanol/water-mixture were added with stirring within 30 min. Theprecipitate was sucked off, slurried in 1000 ml of hot water, sucked offagain, and the filter cake was washed with 2×200 ml of hot water. Theoff-white powder was dried in a circulating air oven at 70° C. Yield:92.0 g (95%). Inherent viscosity: 0.10 dl/g (0.5 g in 100 ml of DMAc).

Example 2 Synthesis of4,4′-bis-[(2-ethoxy-5-(trans-1-propen-1-yl))phenoxy]diphenylsulfone

To 25.0 g (0.1 mol) of bis(4-fluorophenyl)sulfone in 100 ml ofdimethylacetamide (DMAc), placed in a 750 ml-flask fitted with astirrer, reflux condensor, and thermometer were added 20 g (0,145 mol)of potassium carbonate, and the mixture was heated to 90° C., at whichtemperature 36.8 g (0.21 mol) of vanitrope were added within a fewminutes. The mixture was then heated at 150° C. for 4 hours andsubsequently cooled down to 120° C. 150 ml of 1-methoxy-2-propanol wereadded to the stirred batch, and after cooling to 80° C. 150 ml ofiso-propanol were added followed by 200 ml of water. At room temperaturethe precipitate was separated, filtered off, and crystallized from 400ml of a 3:5 (vol/vol) MTBE/methanol-mixture. Filtration and drying at70° C. yielded 47 g (82.5%) of an off-white crystalline product. Purity:98.4% (area % by HPLC). Melting point: 106-107° C.

Example 2a Synthesis of Vanitrope-Terminated Polyetherethersulfone

54.56 g (0.19 mol) of 4,4′-dichlorodiphenylsulfone, 19.82 g (0.18 mol)of resorcinol, and 34.82 g (0.25 mol) of dry potassium carbonatetogether with 200 ml of N-methylpyrolidone and 70 ml of toluene, wereplaced in a 3-necked flask equipped with a stirrer, reflux condensor,and a Dean-Stark trap. The mixture was then heated at 155° C. for 4hours, after which time water was distilled off and separated by theDean-Stark trap. The mixture was further heated for 2 hours at 180° C.After cooling down to 140° C., 3.5 g (0.02 mol) of vanitrope and 1.95 g(0,014 mol) of dry potassium carbonate were added, and the reactionmixture was heated at 155° C. for 4 hours and then heated at 180° C. for2 hours. After cooling to room temperature 1000 ml of a 1:1methanol/water-mixture were added with stirring within 30 min. Theprecipitate was sucked off, slurried in 1000 ml of hot water, sucked offagain, and the filter cake was washed with 5×200 ml of hot water. Theproduct was finally dried in a circulating air oven at 80° C. to yield60.0 g (95%) of an off-white powder. Inherent viscosity: 0.15 dl/g (0.5g in 100 ml of DMAc).

Example 3 Synthesis of1,3-bis[(2-ethoxy-5-(trans-1-propen-1-yl))phenoxy]pyrimidine

To a solution of 14.9 g (0.1 mol) of 4,6-dichloropyrimidine and 37.4 g(0.21 mol) of vanitrope in 250 ml of DMSO were added 69.1 g (0.5 mol) ofpowdered potassium carbonate under vigurous stirring. The stirredmixture was heated under nitrogen at 90° C. for 1 hour and then cooleddown to 15° C. 750 ml of water were added slowly. After stirring thebatch for additional 30 min the precipitated product was filtered offand washed with water. The wet product was stirred in a mixture of 300ml of 1-methoxy-2-propanol and 100 ml of methanol at a temperature of50-70° C., then cooled down to 10° C. and 300 ml of water were added tothe stirred slurry. After stirring for an additional hour the productwas filtered off and washed with methanol. The product was dried at 50°C. in a vacuum oven to yield 35.9 g (83%) of an off-white powder.Purity: 99.5% (HPLC area-%). Melting point: 154-155° C.

Example 4 Synthesis of1,3-bis[(2-ethoxy-5-(trans-1-propen-1-yl))phenoxymethyl]benzene

To a solution of 36.8 g (0.21 mol) of vanitrope in 130 ml ofiso-propanol were added 23.6 g (0.21 mol) of potassium tert-butylate,and the mixture was stirred for 15 min. 17.5 g (0.1 mol) of m-xylylenedichloride dissolved in 30 ml of iso-propanol were then added within afew minutes, and the mixture was stirred for 30 min. The mixture wasthen heated under reflux (82° C.) for 4 hours. Additional 2.3 g ofpotassium tert-butylate were added, and the reaction was heated underreflux for another 2 hours. 400 ml of toluene were then added, and themixture was cooled down to room temperature. Then 350 ml of water wereadded, and the mixture was stirred for 30 min. The toluene phase wasseparated and dried over anhydrous CaCl₂. After separation of CaCl₂, 100ml of toluene were added, the solution was heated up to 60° C., and 50ml of methanol were added. The batch was slowly cooled down to roomtemperature, additional 50 ml of methanol were added, and the mixturewas stirred for 1 hour. The precipitate was then filtered off, washedwith methanol, and dried in a vacuum oven at 35° C. The mother liquorwas concentrated in a rotary evaporator and treated as described aboveto afford the second crop. Combined yield was 33.0 g (72%). Purity: 96%(HPLC area-%). Melting point: 97° C.

Example 5 Synthesis of1,4-bis[(2-ethoxy-5-(trans-1-propen-1-yl))phenoxy]butane

36.8 g (0.21 mol) of vanitrope were suspended in 120 ml of iso-propanolwith stirring at room temperature. 23.6 g (0.21 mol) of potassiumtert-butylate were added, and the mixture was stirred for 30 min. Theexothermic reaction raises temperature up to 30° C. 21.6 g (0.1 mol) of1,4-dibromobutane dissolved in 40 ml of iso-propanol were added within20 min. The batch was heated up to 80° C. and stirred for 14 hours. 200ml of toluene and 350 ml of water were added, the mixture was stirredfor 15 min, and then the phases were separated at 50° C. The organicphase was washed with diluted hydrochloric acid (pH 4), phases wereseparated again, and the organic phase was dried over anhydrous CaCl₂.The toluene was then stripped off in a rotary evaporator. The residuewas dissolved in 200 ml of n-hexane at 69° C. and the solution wasallowed to cool down to room temperature to yield light beige crystalls,which were filtered off and dried in a vacuum oven for 10 hours at 40°C. Yield: 14.2 g (34.6%). Purity: 99.2% (HPLC area-%). Melting point:115° C.

Example 6 Synthesis of 1,3-bis[3-[2-ethoxy-5-(trans-1-propen-1-yl)phenoxy]-2-hydroxypropyl]benzene

35.65 g (0.2 mol) of vanitrope, 22.22 g (0.1 mol) of resorcinoldiglycidyl ether, and 0.15 g (0.35 mmol) of triphenylethylphosphoniumiodide were charged into the reaction flask and the mixture was heatedunder nitrogen atmosphere at 120° C. for 2 hours. Then the temperaturewas increased to 140° C. and the mixture was heated for 12 hours. Aftercooling down to 80° C., 150 ml of methanol were added to dissolve thepartially solidified material. The solution was slowly cooled to roomtemperature to crystallize the product. After filtration the filter cakewas washed on a sucking funnel with 20 ml of methanol to afford 65 g ofa crude wet product still containing 4,8% of vanitrope. Crude purity:92.5% (HPLC area-%). The crude product was further purified to a purityof 98.5% by recrystallization from methanol. Melting point ofrecrystallized material: 115-116° C.

II. Mixtures of BMI (II) with Vanitrope-Substituted Compounds (I)

The curable compositions of the invention can be obtained according tothe following general processes:

a. Melt Process

The polymaleimide of formula (II), or a mixture of two or morepolymaleimides, and at least one2-ethoxy-5-(trans-1-propen-1-yl)phenoxy-substituted compound of formula(I) were melt-blended in a temperature range of 120-140° C. until aclear melt was obtained. Subsequently, the melt thus obtained wasfurther heated in the same temperature range for a time sufficient toobtain a stable melt. Finally, the melt was degassed under reducedpressure of 20 hPa [15 mm Hg] for 2-10 minutes to obtain a curablecomposition.

b. Solvent-Assisted Process

The polymaleimide of formula (II), or a mixture of two or morepolymaleimides, and at least one2-ethoxy-5-(trans-1-propenyl)phenoxy-substituted compound of formula(I), and optionally one additional co-monomer and toluene in asolids-to-solvent weight ratio of 1:1 were heated at 90-100° C. until aclear solution was obtained. Subsequently, toluene was stripped offunder reduced pressure, and the temperature was simultaneously increasedto 120° C. Finally, the mixture was degassed for 30 minutes underreduced pressure of 20 hPa [15 mm Hg] to obtain a curable composition.The resin/solvent ratio may vary, depending on the solubility ofcomponents.

c. Reactivity Measurements

c. 1. Differential Scanning Calorimetry (DSC)

Differential scanning calorimetric (DSC) traces, obtained at a definedheating rate (10° C./min) in the temperature range from 20 to 380° C.,were used to characterize the cure kinetics of the curable compositionsof 2-ethoxy-5-(trans-1-propen-1-yl)phenoxy-substituted compound (I) andBMI (II). The cure exothermic maximum, T_(MAX), represents thetemperature of maximum heat release at the specified heating rate. Thehigher is T_(MAX) the slower is the cure of a resin. The T_(MAX) data ofcurable compositions of BMI (II) and2-ethoxy-5-(trans-1-propen-1-yl)phenoxy-substituted compounds (I),prepared in examples 7 through 16, are compiled in Table 1.

c. 2. Hot-Plate Gel Time

Being a standard measure of resin reactivity, the gel time was measuredby placing 1 g of the resin on an electrically heated metal block with apolished surface, which is capable of being maintained at temperaturesbetween 130° C. and 230° C., and continuous stirring and probing themolten sample with a wooden rod, as described in the ISO 8987 and ASTMD4217 norms. The gelation results of curable compositions of BMI (II)and 2-ethoxy-5-(trans-1-propen-1-yl)phenoxy-substituted compounds (I),prepared in examples 7 through 16, are compiled in Table 1.

III. Examples 7 Through 15

TABLE 1 Reactivity data of curable compositions of BMI (II) and2-ethoxy-5-(trans-1-propen-1- yl)phenoxy-substituted compounds (I).Molar ratio of all BMI (II)/co-monomer (I) mixtures was 1,0:0,5 mol/mol,respectively. DSC heating rate 10° C./min. Bismaleimide ReactivityExample Co-monomer (I) BMI DSC T_(MAX) Gel time at T (sec) No. fromExample No. (II) (° C.) 150° C. 170° C. 7 1 MDAB 175 346 96 8 1 BAC-BMI208 391 131 9 1 C353A 187 441 160 10 2 ME-MDAB 214 491 210 11 3 C353A197 682 150 12 4 MDAB 157 133 42 13 4 ME-MDAB 204 609 220 14 5 C353A 188217 74 15 6 C353A 185 110 91 MDAB = 4,4′-bismaleimidodiphenylmethane;BAC-BMI = 1,3-bis(maleimidomethy)cyclohexane; C353A = eutectic mixtureof 4,4′-bismaleimidodiphenylmethane, 2,4-bismaleimidotoluene, and1,6-bismaleimido-2,2,4(4,4,2)-trimethylhexane stabilized withhydroquinone, commercial bismaleimide mixture available from EvonikIndustries; ME-MDAB = bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane.

IV. Comparative Examples 16 to 21

TABLE 2 Comparative reactivity data of BMI(II)/ commercial co-monomermixtures. Molar ratio of all BMI (II)/co-monomer comparative mixtureswas 1,0:0,5 mol/mol, respectively. DSC heating rate 10° C./min.Bismaleimide Reactivity Example Comparative BMI DSC T_(MAX) Gel time atT (sec) No. co-monomer (II) (° C.) 150° C. 170° C. 16 TM124 MDAB 2595261 1592 17 TM124 ME-MDAB 297 >10000 >4500 18 TM124 C353A 266 5137 151019 TM123 MDAB 230 4202 1086 20 TM123 ME-MDAB 284 9497 2833 21 TM123C353A 236 5090 1520 TM124 = o,o′-diallylbisphenol-A (commercial productavailable from Evonik Industries); TM123 =4,4′-bis(o-propenylphenoxy)benzophenone (commercial product availablefrom Evonik Industries); MDAB = 4,4′-bismaleimidodiphenylmethane;ME-MDAB = bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane; C353A =eutectic mixture of 4,4′-bismaleimidodiphenylmethane,2,4-bismaleimidotoluene, and1,6-bismaleimido-2,2,4(4,4,2)-trimethylhexane stabilized withhydroquinone, commercial bismaleimide mixture available from EvonikIndustries.

Comparison of gel time data of examples 7 to 15 (vanitrope-basedmixtures, Table 1) with the corresponding gel time data of examples 16to 21 (non-vanitrope based mixtures, Table 2) clearly demonstratessignificantly faster curing obtained for the mixtures comprising thevanitrope type co-monomers of this invention. The results obtained bydifferential scanning calorimetry (DSC), are in accord with the resultsobtained from gel time measurements. DSC maxima of the correspondingformulations, T_(max), were found at lower temperatures, for the fastercuring mixtures comprising the vanitrope type co-monomers of thisinvention.

While the invention has been described in detail, modifications in thespirit and scope of the invention will be readily apparent to those ofskill in the art. Those of ordinary skill in the art will appreciatethat the foregoing description is by way of example only, and is notintended to limit the invention.

1: A [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compoundaccording to formula (I)

wherein D is an x-functional group; and x is an integer ≧2; with theproviso that the x-functional group D is not a polycarbonate with anaverage molar mass in the range of 15000 g/mol to 150000 g/mol. 2: The[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compound accordingto claim 1, wherein D is a difunctional group selected from the groupconsisting of: (a) alkylene or alkenylene group with 2 to 12 carbonatoms; (b) cycloalkylene group with 5 or 6 carbon atoms; (c)heterocyclic group with 3 to 5 carbon atoms and at least one nitrogensulfur or oxygen atom in the heterocyclic ring; (d) mono- ordicarbocyclic group; (e) bridged multicyclic group consisting of atleast two groups selected from the following: monocarbocyclic aromaticgroups, dicarbocyclic aromatic groups, cycloalkylene groups; whereinthese groups are linked to each other by direct carbon-carbon bonds orby divalent groups; and (f) one of the groups of the followingstructures

wherein AR¹, AR², AR³, AR⁴, AR⁵ and AR⁶ are independently difunctionalaliphatic or aromatic residues; and wherein n is an integer selected inthe range from 2 to 100 and represents the number of repeatingstructural units in the polymer backbone; (g) group of the followingstructure

wherein R²⁶ is a monofunctional group selected from the group consistingof: (1) alkyl or alkenyl group with 2 to 12 carbon atoms, (2) cycloalkylgroup with 5 or 6 carbon atoms, (3) aryl group with 6 to 12 carbonatoms, and (4) [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-group. 3: The[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compound accordingto claim 1, wherein D is a difunctional group selected from the groupconsisting of:

wherein n is an integer selected in the range from 2 to 100 andrepresents the number of repeating structural units in the polymerbackbone. 4: A curable composition, comprising: i. at least one[(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-terminated compound accordingto formula (I)

wherein D is an x-functional group; and x is an integer ≧2; and ii. atleast one polyimide of formula (II)

wherein B is a difunctional group containing a carbon-carbon doublebond, and A is a y-functional group; and y is an integer ≧2. 5: Thecurable composition according to claim 4, wherein D is a difunctionalgroup selected from the group consisting of: (a) alkylene or alkenylenegroup with 2 to 12 carbon atoms; (b) cycloalkylene group with 5 or 6carbon atoms; (c) heterocyclic group with 3 to 5 carbon atoms and atleast one nitrogen sulfur or oxygen atom in the heterocyclic ring; (d)mono- or dicarbocyclic group; (e) bridged multicyclic group consistingof at least two groups selected from the following: monocarbocyclicaromatic groups, dicarbocyclic aromatic groups, cycloalkylene groups;wherein these groups are linked to each other by direct carbon-carbonbonds or by divalent groups; (f) one of the groups of the followingstructures

wherein AR¹, AR², AR³, AR⁴, AR⁵ and AR⁶ are independently difunctionalaliphatic or aromatic residues; and wherein n is an integer selected inthe range from 2 to 100 and represents the number of repeatingstructural units in the polymer backbone; and (g) a group of thefollowing structure

wherein R²⁶ is a monofunctional group selected from the group consistingof: (1) alkyl or alkenyl group with 2 to 12 carbon atoms, (2) cycloalkylgroup with 5 or 6 carbon atoms, (3) aryl group with 6 to 12 carbonatoms, and (4) [(2-ethoxy-5-trans-1-propen-1-yl)-phenoxy]-group. 6: Thecurable composition according to of claim 4, wherein the y-functionalgroup A in the polyimide according to formula (II) is selected from thefollowing difunctional groups: a) alkylene group with 2 to 12 carbonatoms; b) cycloalkylene group with 5 to 6 carbon atoms; c) heterocyclicgroup with 4 to 5 carbon atoms and at least one nitrogen, oxygen, orsulphur atom in the ring; d) mono- or dicarbocyclic group; e) bridgedmulticyclic group consisting of at least two groups selected from thefollowing: monocarbocyclic aromatic groups, dicarbocyclic aromaticgroups, cycloalkylene groups; wherein these groups are linked to eachother by direct carbon-carbon bonds or by divalent groups; and f) agroup defined by formula (III)

wherein R⁹ is one of the following groups

7: A curable composition according to claim 4, wherein B in thepolyimide according to formula (II), is selected from the followingdifunctional groups:

8: A curable composition according to claim 4, wherein the polyimideaccording to formula (II) is selected from the group consisting of:4,4′-bismaleimidodiphenylmethane,bis(3-methyl-5-ethyl-4-maleimidophenyl)methane,bis(3,5-dimethyl-4-maleimidophenyl)methane,4,4′-bismaleimidodiphenylether, 4,4′-bismaleimidodiphenylsulfone,3,3′-bismaleimidodiphenylsulfone, bismaleimidodiphenylindane,2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene,1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene,1,4-bismaleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane,1,6-bismaleimido-(2,2,4-trimethyl)hexane,1,6-bismaleimido-(2,4,4-trimethyl)hexane,1,4-bis(maleimidomethyl)cyclohexane,1,3-bis(maleimidomethyl)cyclohexane,1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene,and 1,4-bis(maleimidomethyl)benzene. 9: A curable composition accordingto claim 4, wherein D is a difunctional group selected from the groupconsisting of:

wherein n is an integer selected in the range from 2 to 100 andrepresents the number of repeating structural units in the polymerbackbone, and wherein the polyimide according to formula (II) isselected from the group consisting of: 4,4′-bismaleimidodiphenylmethane,bis(3-methyl-5-ethyl-4-maleimidophenyl)methane,bis(3,5-dimethyl-4-maleimidophenyl)methane,4,4′-bismaleimidodiphenylether, 4,4′-bismaleimidodiphenylsulfone,3,3′-bismaleimidodiphenylsulfone, bismaleimidodiphenylindane,2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene,1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene,1,4-bismaleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane,1,6-bismaleimido-(2,2,4-trimethyl)hexane,1,6-bismaleimido-(2,4,4-trimethyl)hexane,1,4-bis(maleimidomethyl)cyclohexane,1,3-bis(maleimidomethyl)cyclohexane,1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene,and 1,4-bis(maleimidomethyl)benzene. 10: A curable composition accordingto claim 4, further comprising a cure accelerator or a cure inhibitor.11: A process for the manufacture of a curable composition according toclaim 4, comprising blending the components of the composition using apowder-, melt-, or solvent-assisted blending process resulting in asolid, low-melting, or tacky curable composition. 12: A curablepre-polymer obtainable from a curable composition according to claim 4by a process comprising heating the curable composition to a temperaturein the range of 50° C. to 250° C., for a time sufficient to obtain thepre-polymer which is still formable upon the application of heat and/orpressure. 13: A crosslinked polymer obtainable from the curablecomposition according to claim 4 by a process comprising the heating thecurable composition to a temperature in the range of 70° C. to 280° C.for a time sufficient to obtain a polymer. 14: A process for themanufacture of a composite material, comprising: combining a curablecomposition according to claim 4 with a fibrous or particulatereinforcement, and curing a resultant product. 15: A composite materialobtainable by a process according to claim
 14. 16: A process for themanufacture of a composite material, comprising: combining a curablepre-polymer according to claim 12 with a fibrous or particulatereinforcement, and curing a resultant product.